Displaying each Asian characters in their own fonts?
I accidentally discovered this but, I could get the result I wanted by just checking the "Translation" checkbox in Interface in the Preference dialogue. Blender's version is 2.81a.



Even though "Translation" is checked, it did not change the UI language from English. I wonder why this option is turned on by default. Maybe there is some side effects like slow UI or something? I will add here if I later discover some problems with this, but so far, it seems working.



Update

There seems to be a big problem. When it is checked, Blender seems to be using "international fonts". But that makes zooming on the Shade Editor very slow. It is not unusably slow, but makes it unpleasant to use Blender. I tried to report it as a bug, but found an existing entry for this. The entry was closed because it is an "old known TODO", meaning the developers are currently do not have the time to fix this and will not fix this.

Blender is probably written in OpenGL, and I don't know why zooming of a few lines of texts should be this slow just because "international fonts" are used, because web browsers like Chrome zooms fine with Asian fonts, but anyway, I think I will only check the "Translation" when I have to open someone else's file that used Asian texts for the names of objects.